ArrayDeque.getFirst() in Java

ArrayDeque.getFirst(): This method is available in java.util.ArrayDeque class of Java.

Syntax:

E java.util.ArrayDeque.getFirst()

This method retrieves but does not remove, the first element of this deque.

Parameters: NA

Returns: the head of this deque.

Throws:

NoSuchElementException - if this deque is empty.

Approach 1: When no exception

Java

import java.util.ArrayDeque;

public class ArrayDequegetFirst {
    public static void main(String[] args) {

        ArrayDeque<Integer> arrayDeque = 
                       new ArrayDeque<Integer>();

        arrayDeque.add(1);
        arrayDeque.add(4);

        System.out.println(arrayDeque.getFirst());

    }
}

Output:

1

Approach 2: NoSuchElementException 

Java

import java.util.ArrayDeque;

public class ArrayDequegetFirst {
    public static void main(String[] args) {

        ArrayDeque<Integer> arrayDeque = 
                     new ArrayDeque<Integer>();

        System.out.println(arrayDeque.getFirst());

    }
}

Output:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.ArrayDeque.getFirst(ArrayDeque.java:402)